The invention refers to a process according to the preamble of Patent Claim 1 and a device or apparatus for the implementation of this process according to the preamble of Patent Claim 3.
The known processes and devices of this type are designed so that each individual measuring point is connected with the central evaluation station, e.g., a data processing device with a monitor, via a separate transmission line used by it only and the individual measuring points are interrogated or polled one after the other via the lines at the location of the evaluation station.
This state of the art requires a very large installation expenditure.
The problem forming the basis for the invention is to create a process according to the preamble of Patent Claim 1 that makes possible reliable interrogation of the individual measuring points with a much lower installation expenditure than the above-mentioned processes required for its realization and a device for the implementation of this process.
The problem above is solved with the object of Patent Claim 1 and with the object of Patent Claim 3.
With the process according to the invention, only one single line with a few wires is required for the longest link from the group of measuring points belonging together to the central evaluation station, since the measuring points of this group are assembled at the network device which, controlled from the central evaluation station, produces the connection to the individual measuring points in a predetermined sequence, whereby the network device is connected with an output of the central evaluation station, for which a single line with a few wires, in principle with only two, is sufficient.
Even in cases when there are several groups of measuring points belonging together, only one single cable with these few wires is required between these groups and/or between the individual network devices assigned to them in each case and one of these network devices to the central evaluation station when operating according to the process according to the invention.
Patent Claim 2 is concerned with a preferred design of the process according to Patent Claim 1.
Patent Claim 3 is concerned with a device suited for implementation of the process according to the invention and Patent claims 4 to 6 refer to preferred designs of the device according to Patent Claim 3.